Manhole cover-plate.



E. OLDMAN. MANHOLE COVER PLATE. APPLICATION FILED JAN. 15, 1909.

WITNESSES krgmy.

ANDREW. B: GRAHAM 00., rumu-umoemvnzns. WASWNG'ON, n. c.

Patehted Nov. 30, 1909.

STATES PATENT OFFIUE.

EDWARD OLDMAN, OF BUFFALO, NEW YORK, .ASSIGNOR T0 FARRAR & TREFTS, OF

BUFFALO, NEW YORK, PARTNERS.

MANHOLE COVER-PLATE.

Specification of Letters Patent.

Patented Nov. 30 1909.

To all whom it may concern Be it known that I, EDWARD OLDMAN, a citizen of the United States of America, and resident of Buffalo, county of Erie, State of New York, have invented certain new and useful Improvements in Manhole Cover- Plates, of which the following is a specification.

This invention relates to cover plates for hand holes, man holes, or sludge holes of steam boilers, tanks, or like container vessels.

An object of the invention is the production of a wrought iron or pressed steel cover plate made of a single piece of metal, pressed or stamped into the desired shape and provided with means for engaging retaining rods, or bolts. v

A .further object is the production of a cover plate which is cheap to manufacture, of simple and light construction, of great strength and durability and which will eliminate all possibility of leakage.

These and other objects I attain in an apparatus embodying the features herein described and illustrated in the accompanying drawings.

In the drawings, Figure 1 is a plan view of a cover plate embodying my invention. Fig. 2 is a partial side view and a partial sectional elevation along line aa of Fig. 1, and is shown in connection with a retaining rod, or bolt. Fig. 8 is a side View of a yoke. Fig. 4 is a sectional view along the line b?) of Fig. 1.

The plate, 3, disclosed in the drawings, is preferably pressed while hot from a fiat steel plate, and so formed that a bearing flange, 4, is provided around its edge, which is adapted to seat against the shell of the boiler or tank, around the edge of the hole to be covered.

The plate is so shaped that a longitudinally extending depression isformed on the outer face and a corresponding ridge, or lug, 5, is formed on the inner face. The ridge, 5, is so shaped that it adds materially to the strength and stiffness of the cover plate.

Stay pins, 6, are secured in tapped holes, 7, which are provided in the opposite walls of the depression, or in the opposite legs of the ridge, 5. The holes, 7, are arranged in pairs. The two holes of each pair are located in opposite legs of the reinforcing ridge and are axially alined. Each stay pin, 6, is continuously threaded and is inserted through the alined tapped holes, 7, of one pair and is permanently secured in place on the plate by being riveted over at its ends.

When the pins are in place they subtend the depression formed on the outer side of the plate and perform the double function of adding to the strength and rigidity of the plate and of providing means for holding the plate against its seat. The latter function is accomplished through the agency of retaining bars, or bolts, 8, each of which is preferably provided with a hooked end, 9, adapted to engage one of the stay pins, 6. The hooked end, 9, of each bar extends into the depression on the outer side of the cover plate and engages one of the stay pins. The outer end of each retaining hook engages and is secured in place by a yoke, 10, of ordinary construction.

The cover plate is preferably elliptical, or elongated, so that it can be introduced into the interior of the tank through the hole which it is adapted to close. Aside from the reinforcing lug, 5, the cover plate may be of any desired contour that will give the necessary strength and rigidity.

In accordance with the patent statutes, I have illustrated and described what I now consider to be a preferred embodiment of my invention, but I desire it to be understood that I do not limit myself to the apparatus shown, and that various changes and modifications may be made without departing from the spirit and scope of my invention.

What I claim is:

1 A man hole cover comprising a plate provided with a longitudinally extending reinforcing means, stay pins rigidly secured to said plate so as to laterally reinforce said plate and means for engaging said pins and securing said plate in place.

2. A man or hand hole cover comprising a plate provided with an integrally formed reinforcing ridge and stay pins extending transversely of said ridge and riveted to said plate.

3. A man or hand hole cover plate comprising a pressed steel plate provided with a longitudinally extending reinforcing ridge pressed into the plate and a stay pin extending transversely of the ridge and rigidly secured to the plate.

4. A man or hand hole cover plate for boilers comprising a pressed steel plate provided With a longitudinally extending depression and stay pins extending transversely oil? said depression and rigidly secured to the ate. p 5. A man or hand hole cover comprising a pressed steel plate provided With a longitudinally extending reinforcing ridge pressed into said plate, and stay pins secured into tapped holes provided in the legs of said ridge for reinforcing said plate and for engaging retaining hooks for holding said plate in place.

6. A man or hand hole cover comprising a pressed steel plate, a longitudinally extendling ridge pressed into said plate, stay pins located in the depression formed by said i ridge, extending transversely of said depression and rigidly secured to the legs of said ridge and retaining bolts for engaging said stay pins and for securin said cover in place. 20

EDWiiRD OLDMAN. Witnesses E. E. ARNOLD,

EDW. E. MENIG. 

